CareerCup

{
SELECT first_name "First Name"
FROM employees;
}

I think you are being asked whether you should use char versus varchar for datatype. Even though char may take up more space it is apparently more efficient because of the way varchars are stored.
They are also asking you about how you might index the table. Indexes are great for speeding up reads but slow down updates, inserts and deletes. A clustered index on firstname/lastname is great where you are predominantly doing reads.